In the historical past, many windows and doors were manufactured with true divided lights. More specifically, their sashes had muntins that defined rectangular openings. A separate glass pane was disposed in each of the rectangular openings and secured with glazing or trim. In recent years, demand for more energy efficiency has lead to windows and doors having a single glass or glazing unit, which usually is an insulated double pane unit secured within a surrounding window or door frame. While this is more energy efficient and simplifies manufacturing, some consider the appearance of a single large glass pane to be plain or otherwise objectionable. Accordingly, grilles have been developed that can be installed in a window sash or door panel overlying the glazing unit. These grilles are profiled to mimic the look and architectural appearance of historical divided light windows, especially from a distance. Grilles can be installed on the inside, the outside, or both sides of a window sash or door panel to reproduce in greater or less detail the appearance of a true divided light window or door.
The option to attach grilles to windows and doors to create the appearance of true divided lights is a highly desirable feature of a window or door product line. Finding suitable attachment techniques has proven problematic, however, for several reasons. For example, the grille, when attached, should appear to be an integral part of the window or door, with no visible attachment components. Further, the grille must be easily removable from the window or door to allow effective cleaning of the underlying glazing unit. Finally, the attachment mechanism should not mar or scratch the finishes of wood or clad surfaces when the grille is repeatedly attached to and removed from the window or door.
Previous solutions to these and other grille attachment challenges have proven only partially satisfactory. Some such solutions employ a plunger system wherein extendable plungers in the ends of the crisscrossing grille components can be extended to engage grommets inserted into the visible part of a sash or door panel surrounding a glazing unit. Unfortunately, these grommets necessitate additional fabrication, and, once installed, accommodate only a single grille configuration. Also, if a user decides not to apply the grilles or to remove them, the window sash or door panel is left with visible grommets which have no apparent function, a situation considered undesirable by many. Additionally, if during production and after installation of the grommets, a sash is found to have a defect, especially a defect at or near an end, it must be discarded rather than salvaged by cutting off the ends of the lineals and using them for a smaller window. This is because cutting off an end of a lineal or the entire sash will no doubt place the grommets in the wrong locations for receiving a grille. U.S. Pat. Nos. 5,437,133 and 6,230,456 disclose grille attachment systems using grommets of the type just described.
Another prior solution, disclosed in U.S. Pat. No. 5,622,017, as well as in other patents owned by the assignee of the present disclosure, involves forming a groove in the visible surfaces of a sash or door panel surrounding a glazing unit. Plungers on the ends of the grille components fit into the groove for holding the grille in place. This solution suffers from at least the problem that the visible groove may not provide the appearance that some customers prefer and may be considered unsightly even when a grille is attached because the groove is still visible. Yet another solution, disclosed in U.S. Pat. No. 6,718,704, also owned by the assignee of the present disclosure, includes metal clips that are forced between the sash lineals and the glazing unit when the grille is installed. While largely effective, the clips may nevertheless have a tendency in some cases, to mar the sash, especially when the sash is made of a softer wood, and generally are visible which can be considered unsightly.
A need therefore exists for an attachment system for securing decorative grilles to window sashes and door panels that addresses these and other shortcomings of prior art attachment solutions. It is to the provision of such an attachment system and to windows and doors incorporating such a system that the present invention is primarily directed.